The invention relates to an aerial for a motor vehicle, with a capacitive coupling to ground in the region of an aerial base and with an aerial wire which, in the installed state, leads to an outer side of the vehicle and is connected to one end of a high frequency line.
German Patent Document DE 91 16 508 U1 discloses an aerial for a motor vehicle which can be fitted from the outside onto the body of a motor vehicle. An aerial tip for guiding the aerial wire can be screwed into an aerial base whose housing can be mounted on the outer skin of the body of a motor vehicle. The aerial is provided with a capacitive ground coupling, the aerial cable being conductively connected by a capacitive plate to the bottom of the aerial base. Furthermore, a dielectric is arranged between the capacitive plate and the outer skin of the body of the vehicle. As a result of the capacitive ground coupling, no direct connection is necessary between the ground of the aerial and the body of the vehicle.
Generally, known vehicle aerials have an upper part and a lower part which are screwed to one another during mounting, and secure between them the sheet metal of the body of the vehicle. The ground contact is usually made using sheet-metal claws. The aerial must be mounted from both sides of the body sheet metal.
The object of the present invention is to provide a motor vehicle aerial of the type mentioned above, which has the advantages of capacitive ground coupling and can be easily anchored in the body of the motor vehicle from one side.
This object is achieved according to the invention in that the aerial base, the ground coupling, the aerial wire and the connected end of the high frequency line are embedded by bonding, locking or casting in a single component elastomer body which is provided with a configuration, such as a ring, groove or flange, which locks in an opening in a wall of the body of the motor vehicle. (The high frequency line can be provided in the form of a cable or a plug.) By embedding the individual elements of the aerial of the motor vehicle in a single-component preform, joining or assembling the individual parts of the motor vehicle aerial is dispensed with. As a result of the locking arrangement, it is possible to anchor the motor vehicle aerial easily from one side, preferably from an underside, in a wall of the vehicle body, for example a vehicle body panel. The elastomer body is easily pushed from below, through the opening in the wall of the body of the vehicle to such an extent that the locking configuration of the elastomer body locks in the opening. The shape of the elastomer body can be adapted to the spatial circumstances in which the motor vehicle aerial has to be accommodated in the body of the vehicle.
In a refinement of the invention the elastomer body has a disk shaped base which can be positioned below the wall of the vehicle body, and the end of the high frequency line and a contact plate for capacitive ground coupling are embedded therein. The contact plate is in contact with the high frequency line, and is free towards one upper side. The connection of the high frequency line and the ground coupling is thus made invisible on the underside of the wall of the vehicle body.
In a further embodiment of the invention, the elastomer body has an elongated peg-like tip which connects to the base and (in the mounted state) projects through the opening in the wall of the vehicle body towards the outside, with the aerial wire at least partially molded therein. (Molding in this case also includes locking and bonding.) The peg-like tip projects horizontally from the outside of the wall in the vehicle body in order to perform reliably the respective transmitting or receiving function of the aerial.
In a further refinement, the elastomer body is assigned a connector which can be pushed axially into it from below. As a result mounting and a sealing effect are promoted.
In a further refinement of the invention, for locking in the opening in the wall in the vehicle body, the elastomer body has, between the tip and the base, a circumferential annular groove whose internal diameter is smaller than that of the opening. This annular groove also serves to provide a seal, it being possible for sealing also to take place radially.
In a further refinement a lower edge of the tip is provided in the region of the annular groove with a circumferential sealing lip for sealing the opening from one outer side of the wall of the vehicle body. As a result, the elastomer body additionally fulfills a sealing function in that it protects the opening in the wall in the vehicle body towards the outside against the penetration of wet or dampness. In other exemplary embodiments according to the invention other seals are provided which are effective from the inside or radially.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.